Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Rufan- und rufabschalte-detektoranordnung zur verwendung in einer teilnehmerschaltung einer fernsprechanlage, insbesondere fernsprechnebenstellenanlage
Changeover switch circuitry for telephone party line - uses central control unit with microcomputer setting contacts of bistable relays blocking or connecting each subscriber